chromeos: Rename ash::WmShelf to Shelf

ash/mus/context_menu_mus.h

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef ASH_MUS_CONTEXT_MENU_MUS_H_
 #define ASH_MUS_CONTEXT_MENU_MUS_H_
 
 #include "ash/shelf/shelf_alignment_menu.h"
 #include "base/macros.h"
 #include "ui/base/models/simple_menu_model.h"
 
 namespace ash {
 
-class WmShelf;
+class Shelf;
 
 // Context menu for mash.
 // TODO: Mimic logic in LauncherContextMenu. http://crbug.com/640693
 class ContextMenuMus : public ui::SimpleMenuModel,
                        public ui::SimpleMenuModel::Delegate {
  public:
-  explicit ContextMenuMus(WmShelf* wm_shelf);
+  explicit ContextMenuMus(Shelf* shelf);
   ~ContextMenuMus() override;
 
   // ui::SimpleMenuModel::Delegate overrides:
   bool IsCommandIdChecked(int command_id) const override;
   bool IsCommandIdEnabled(int command_id) const override;
   void ExecuteCommand(int command_id, int event_flags) override;
 
  private:
   enum MenuItem {
     MENU_AUTO_HIDE,
     MENU_ALIGNMENT_MENU,
     MENU_CHANGE_WALLPAPER,
   };
 
-  WmShelf* wm_shelf_;
+  Shelf* shelf_;
   ShelfAlignmentMenu alignment_menu_;
 
   DISALLOW_COPY_AND_ASSIGN(ContextMenuMus);
 };
 
 }  // namespace ash
 
 #endif  // ASH_MUS_CONTEXT_MENU_MUS_H_